According to recent safety statistics published by the Federal Railroad Administration (FRA), the total impact of damage caused by all reported derailment accidents in the US amounts to hundreds of millions of dollars annually, more than 10% of which were due to track problems. For safety and efficiency reasons, railroad track inspection for physical defects and irregularities is required to be performed on a regular basis in order to maintain a high standard of track condition. Rail inspection generally includes a wide variety of specific tasks, ranging from locating and evaluating the condition of different rail fastener components (tie plates, anchors, joint bars, etc.) to monitoring rail surfaces, alignments and curvatures, to detecting sequence-level track design non-compliances.